Aerosol containers containing a wide variety of active components such as insect repellents, insecticides, hair sprays, creams or foams and so on have been marketed widely for household, commercial or industrial purposes.
In conventional aerosol containers, the ejection outlet is normally a tubular element which, when depressed into the body of the container releases the contents which are held under pressure. When the applied force at the valve stem is removed, the valve stem returns to its equilibrium position simultaneously stopping the outward flow of the contents of the container. In one type of aerosol containers a small knob (actuator) is fitted over the valve stem such that when the actuator is depressed the valve stem is simultaneously depressed causing the contents of the container to be released via an outlet in the actuator. Release of the pressure at the actuator returns the valve stem to its equilibrium position. Very often the contents of the aerosol container spill over onto the finger of the operator. To operate the actuator an enclosing cover has to be removed first to expose the actuator. Such covers can often be misplaced by the end-users.
In another type of aerosol container cap, the cap is designed with the actuator as part of its total structure whereby the release of the contents is done by depressing a certain part of the cap (trigger). The contents of the aerosol goes through a certain part of the cap. This is called a "spray through cap". However, in this type of cap the "trigger" is not protected from accidental pressing of the cap by the user. Although in this type of cap, the hand is not soiled by the spillage of the aerosol contents, the danger or inconvenience of accidental spraying of the contents is present.